Prior packet transmission and switching systems were employed primarily to transmit data. In modern packet transmission systems it is also desirable to transmit voice band signals. Heretofore, buffer memories having a large number of memory stages were used to smooth random packet load variations prior to transmission of the packets. This increase in memory size causes packets to experience long delays through a packet network, if that nework is busy, i.e., processing many packets. In packet transmission and switching systems that also transmit voice signals, any significant delay experienced by the individual packets is undesirable because it results in signal impairments that are annoying to the subscribers.
One possible solution to the delay problem is to use a so-called "shorter" packet buffer memory, i.e., one with fewer storage stages. Use of such a shorter buffer memory causes packet buffer memory overflow problems if the buffer memory is processing many packets which, in turn, cause loss of packets. Such loss of packets causes unwanted and annoying gaps in the reconstructed speech signal. The packet buffer memory overflow problem may be avoided by reducing the packet transmission load on the system, thereby reducing the packet generation rate. This however, is economically undesirable.